In a differential amplifier circuit of the related art, common-mode voltage (current) is detected from each output signal in order to set the common-mode voltage of the output signal, and the detected common-mode voltage (current) is fed back to the output signal. Therefore, in the differential amplifier circuit of the related art, there is a problem in which power consumption is increased in order to set the output common-mode voltage.
For instance, there is a proposed differential amplifier circuit in which the output common-mode voltage is set by detecting and feeding back input common-mode voltage. In this differential amplifier circuit, a separate amplifier circuit is necessary besides the differential amplifier circuit in order to compare the input common-mode voltage with the set voltage. Accordingly, extra power is consumed in the separate amplifier circuit.
Further, there is another differential amplifier proposed, in which three-input amplifier is used to set the input common-mode voltage. In this amplifier circuit, the input common-mode voltage can be set, but the output common-mode voltage cannot be set.